first try to set your mind to a particular model(s). If you want to buy 2000+ models or you can live with older model. if you want to buy the most famous 90,91 model.
then try to get a idea of the budget, 50k is the limit for even 2007 model, newer then this and you might buy a brand new one instead.
so keep in mind for a 50K budget, Now when u r spending 50K on purchasing a bike you should take a real good look at its condition, u r not good with bikes and engines so i suggest you hire the services of a good mechanic, he will take max 2K commision and will save your life.
try to buy bike which can easily be transferred to your name and do ur complete satisfaction abt the docs too, i think thats all.
FC bhae can be a real help. un kay pechay par jao